U.S. Army Private First Class Bradley Manning accused of sharing thousands of classified government documents with WikiLeaks, knew that the information would aid enemies of the U.S., a prosecutor argued Monday.

Manning, facing a court martial on 12 charges at Fort Meade, Maryland, endangered U.S. national security when he “systematically harvested” thousands of classified documents and allowed them to be posted to the Internet, prosecutor Captain Joe Morrow said.

The classified documents had “great value to our adversaries, and in particular, our enemies,” Morrow said. “This is a case that shows what happens when arrogance meets access to sensitive information.”

Manning selectively shared documents that he believed other U.S. citizens had a right to see, countered David Coombs, his lawyer. Manning, now 25, was young and naive, but “well-intentioned,” Coombs said in his opening statement.

Manning was hoping to spark a public debate about the Iraq war when he shared documents about detainees at Guantanamo Bay and a video of a helicopter killing two journalists, Coombs said. “He released the documents because he wanted to make the world a better place,” the lawyer said.

The military documents Manning shared were historical records that didn’t endanger troops and the U.S. Department of State cables he shared were widely available to hundreds of thousands of users of the Secure Internet Protocol Router Network (SIPRNet), a computer network used by the U.S. Department of Defense and the State Department, Coombs said.

“He started to see that this information should be public,” Coombs said. “The public should know what’s happening on a day-to-day basis” in Iraq.

Morrow, in his opening statement, detailed a long list of evidence related to Manning’s computer and his access to the SIPRNet. Manning, an Army intelligence analyst, is accused of downloading and transmitting thousands of sensitive documents in late 2009 and early 2010.

Manning took steps to wipe his Macintosh computer twice in early 2010, after he began leaking documents to WikiLeaks, Morrow said. The defendant searched for the term, WikiLeaks, more than 100 times during a deployment in Iraq from late 2009 to early 2010, he said.

Manning signed multiple nondisclosure agreements warning him about disclosing classified data, Morrow said in his hour-long opening statement. Manning’s training warned him about “the enemy’s” use of leaked classified data and its use of WikiLeaks, Morrow said.

Manning faces a life sentence for the pending charges, which include aiding the enemy. In February, he pleaded guilty to 10 lesser charges, including illegally possessing government documents and wilfully communicating them to an unauthorized person. He faces a maximum of 20 years in prison for the charges to which he has pleaded guilty.

Manning is accused of sharing more than 700,000 Iraq and Afghanistan battlefield reports and State Department cables with WikiLeaks. WikiLeaks published documents detailing complaints about detainee abuses in Iraq and a Baghdad airstrike that killed civilians, as well as a number of diplomatic cables sent by State Department employees.

Manning has become a hero to some people who advocate for more open government. Before the court martial began, a group of protestors held signs saying, “Free Bradley Manning,” outside one of Fort Meade’s gates. “Exposing truth is not a crime,” one of the protestors yelled. “Ending war is not a crime.”

Manning’s court martial is scheduled to last until early August.

Updated at 11:20 a.m. PT with new information throughout the article.

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